35 баллов. Уравнение. 1) 2 : х - 0,4 = 1 : 0,4 2) 3 : 4 = х - 1 : 3,2 3) 36 : 35 = 1 : 5х...

Question

35 баллов. Уравнение.
1) 2 : х - 0,4 = 1 : 0,4
2) 3 : 4 = х - 1 : 3,2
3) 36 : 35 = 1 : 5х : 1 : 12

Answer 1

1)
2/x - 0.4 = 1 / 0.4 = 1 / (4/10) = 1 / 4 * 10 = 10 / 4 = 2.5
2/x = 2.5 + 0.4 = 2.9
x = 2 / 2.9 = 0.689655172 ≈ 0.69
2)
3/4 = x - 1/3.2
x = 3/4 + 1/3.2 = 0.75 + 0.3125 = 1.0625
3)
36:35 = 1/(5x)/1/12 = 1 / (5x*1*12) = 1 / (60x)
60x = 1 / (36/35) = 35/36
x = 35/36 / 60 = 35 / (36*60) = 35 / 2160 = 7 / 432 = 0.0162037037 ≈ 0.016

Comments

Огромное спасибо!

Answer 2

1) 2 : x -0.4=1:0,4
2:x-0,4=1:2/5
2:x-0,4=1·5/2
2:x-0,4=5/2
2:x-0,4=2,5
2:x=2,5+0,4
2:x=2,9
x=2,9·2
x=5,8

2)3:4=x-1:3,2
3/4=x-1:16/5
3/4=x-1·5/16
3/4=x-5/16
x-5/16=3/4
x=3/4`⁴+5/16`¹
x=12/16+5/16
x=17/16
x=1 1/16

3) 36:35=1:5x:1:12
36/35=1·1/5x:1·1/12
36/35=1/5x:1/12
1/5x:1/12=36/35
1/5x=36/35·1/12
1/5x=36/420
1/5x=13/140
x=13/140:1/5
x=13/140·5
x=65/140
x=13/28